Arthur - ever the optimist - is always trying out new ideas and drawing Michael and the others into ever madder schemes. A visit to a Safari Park, an evening in a Haunted House, amnesiac detective work, strange religious organisations, gangsters, putting his old band back together and The Soupover, which is like a sleepover, but with much more soup.

A knock on the head results in Arthur joining the police force as a high-ranking detective. It's up to Michael and the gang from the cafe to bring him back to reality.